And the data backs up the impression that this happens more often
in the US than in other countries.

The Americas have by far the worst gun problem in the world, with
the weapons used in 66% of homicides. That compares with 13% to
28% in other regions, according to
a 2013 United Nations report.

The region, which includes North America, South America, and the
Caribbean islands, also has the world's highest murder rate, at
16.3 per 100,000 people. The global average is 6.2 per
100,000, according to the report.

To be fair,
war and conflict-related killings are not included in the UN
chart because they are "outside the realm of intentional
homicide," according to the UN report. Therefore, the report
doesn't account for all types of gun violence.

Still, even Europe is starkly different from the Americas when it
comes to gun homicides. The largest share of homicides in Europe
come from the "other" category. And at three murders per 100,000
people, the region is safer overall than the Americas.

Unsurprisingly, Europe also has a much
lower gun-ownership rate than the US. Many European countries
have fewer than 40 guns per 100 people, whereas the US has closer
to 90 guns per 100 people.

Guns are used in an even greater share of murders in the US than
across the Americas, at 68%:

South America
has also become more violent in recent years. Honduras has
the highest murder rate in the world, and Mexican drug cartels
have worsened the violence in Central America. The UN report
noted that organized crime and gangs accounted for 30% of
homicides in the Americas.